A wearer may be prescribed a positive or negative optical power correction. For presbyopic wearers, the value of the power correction is different for far vision and near vision, due to the difficulties of accommodation in near vision. The prescription thus comprises a far-vision power value and an addition representing the power increment between far vision and near vision. The addition is qualified as prescribed addition. Ophthalmic lenses suitable for presbyopic wearers are multifocal lenses, the most suitable being progressive multifocal lenses.
The inventors have found that right-handed persons and left-handed persons behave very differently when executing certain near vision tasks, such as writing on a sheet of paper.
However, current lens designs do not take into account these behaviour differences.